public ParserType Visit(ParserUnaryOp op)
{
ParserType subExpr = op.Expr.Accept(this);
if (subExpr.Typ != ParserTypeEnum.Pair || !(subExpr is ParserProdType))
{
throw new ArgumentException("Projection must apply to a pair. Current type: " + subExpr.ToString());
}
var prod = subExpr as ParserProdType;
switch (op.OpType)
{
case ParserUnaryOpType.ProjL:
op.Type = prod.Left;
return(prod.Left);
case ParserUnaryOpType.ProjR:
op.Type = prod.Right;
return(prod.Right);
default:
throw new ArgumentException("Unknown Unary Operation");
}
}
public Expression Visit(ParserUnaryOp op)
{
Expression subExpr = op.Expr.Accept(this);
ParserProdType type = op.Expr.Type as ParserProdType;
switch (op.OpType)
{
case ParserUnaryOpType.ProjL:
if (type.Left is ParserNumType)
{
return(new NumProjL(subExpr as AbstractPairExpression));
}
if (type.Left is ParserLogicType)
{
return(new LogicProjL(subExpr as AbstractPairExpression));
}
if (type.Left is ParserProdType)
{
return(new PairProjL(subExpr as AbstractPairExpression));
}
if (type.Left is ParserLambdaType)
{
return(new LambdaProjL(subExpr as AbstractPairExpression));
}
break;
case ParserUnaryOpType.ProjR:
if (type.Right is ParserNumType)
{
return(new NumProjR(subExpr as AbstractPairExpression));
}
if (type.Right is ParserLogicType)
{
return(new LogicProjR(subExpr as AbstractPairExpression));
}
if (type.Right is ParserProdType)
{
return(new PairProjR(subExpr as AbstractPairExpression));
}
if (type.Right is ParserLambdaType)
{
return(new LambdaProjR(subExpr as AbstractPairExpression));
}
break;
default:
break;
}
throw new ArgumentException("Unknown unary operation");
}
